Orange and black Monarch butterflies once again cluster on branches of Eucalyptus trees at Ardenwood Historic Farm. This is one of the "warm" winter destinations of their migratory life cycle that provides a fascinating peek at the natural world around us. Known within the scientific community as Danaus Plexippus, Monarchs are the temperate species of Danaiidae family, a tropical group predominantly represented in the lower latitudes. "When Europeans first came to North America they saw orange and black butterflies which were the color of British King and since then these butterflies have been called Monarch," says Caterina Meyers, Naturalist at Ardenwood Historic Farm.

According to Meyers, these butterflies follow two routes: east of the Rocky Mountains stretching from Canada to Mexico; the other, on the western side, has a terminal point in Baja California. In California, Eucalyptus, Monterey Pines, and Monterey Cypress provide roosting sites, while Oyamel Fir trees are the choice locations in central Mexico. A glance toward the branches reveals clusters of Monarch butterflies, clinging to the trunks and branches.

The migration phenomenon is truly astounding; several generations cover a single route. The butterflies currently seen at the farm represent the fifth generation of those that huddled in the trees last winters. "What you will see next year are the great-great-grandchildren of these present ones," says Meyers. Adult Monarchs that emerge in the spring and early summer have a short lifespan of about four to six weeks in which they complete the cycle of feeding, mating, laying eggs, and dying. In the spring, the migrant butterflies will mate and males die soon after mating while the females begin their flight north looking for milkweed plant on which to lay their eggs after which they also die.

"At present, there are mature butterflies at the farm that will give birth during springtime when it is warmer; it will take about a month for their babies to grow and by late March, they will move to North California and their babies would move to Canada by summer." Each generation according to Meyers moves farther north and then reverses direction when the days grow shorter and colder. What is striking about these butterflies is that each succeeding generation carries a genetic code to return to the same trees every winter. While most butterflies migrate, some might stay behind depending on food availability and warm temperatures.

At Ardenwood Historic Farm, visitors are invited to learn more by watching a slide show followed by a walk or guided tour among the Eucalyptus trees. Local wintering sites also serve as an educational resource for school kids who often visit to understand the butterfly lifecycle. This winter, explore the world of Monarchs and view a true miracle of Mother Nature.

Background information on the Monarchs have been taken from http://www.sdnhm.org/fieldguide/inverts/monarch.html